Rising political tension between the United States and Russia, along with North Korea’s recent missile and nuclear tests, have led to a renewed interest in preparedness for a radiological event—the three most commonly planned-for being: a nuclear reactor incident like Fukushima, a radiological dispersal device (dirty bomb), or nuclear detonation.
While significant progress has been made in the development and stockpiling of medical countermeasures to radiation, as well as detailed planning on when and how to use them, a critical unmet need has been the lack of a high throughput radiation biodosimetry test that can be used to determine individualized levels of absorbed radiation post-event. This has now changed in Europe and in many other countries with the CE IVD marking of DxTerity’s REDI-Dx®* High Throughput Radiation Biodosimetry Test.
Critical support at a crucial time
After a nuclear event, a highly coordinated response with appropriate diagnostic tools and medical supplies will be key to managing the affected population and minimizing loss of life and potentially secondary civil unrest. Although a nuclear reactor incident like Fukushima, a dirty bomb, or nuclear detonation would result in vastly different numbers of individuals requiring medical treatment, the public’s deep-set fear of radiation leads to these events being viewed as almost identical, and in each a large number of the “worried well” could overwhelm emergency response personnel and hospitals. A highly coordinated response with appropriate diagnostic tools and medical supplies is key to effectively managing the affected population and allocating scarce medical resources.
Difficulty testing for radiation dose
Clinical guidelines for the triage and treatment of individuals following a nuclear event are based on a combination of physical injury and absorbed radiation dose. An absorbed dose is measured in Gray (Gy), and individuals receiving a dose of greater than 0.7 Gy are likely to experience Acute Radiation Syndrome (ARS). Doses above 2.0 Gy start to require medical treatment, and 50% of people receiving 5 Gy will die without medical treatment. A total body dose of 8 Gy or higher is usually fatal even with intensive medical treatment.
Unfortunately, accurately predicting an individual’s absorbed radiation dose is not a simple task. Acute Radiation Syndrome (ARS) can be asymptomatic for days to weeks after initial exposure, and the clinical symptoms of exposure are irregular and non-specific. Accurate diagnosis is difficult, which is why there is a need for a test that can estimate the total absorbed radiation dose using an individual’s blood and biological response combined – and this is known as radiation biodosimetry testing.
Current option for dosimetry
Today, the most commonly referenced radiation biodosimetry test is the dicentric chromosome assay (DIC), which has been used for more than 50 years. This cytogenetic test examines chromosome breaks from a cultured blood sample and has proven effective at helping to understand the long-term effects of radiation exposure. However, the DIC protocol is labor intensive, requires highly skilled cytologists, has limited worldwide capacity, and requires rapid, controlled transport to the testing laboratory.
First CE-IVD test for radiation biodosimetry
Recognizing the critical unmet need for radiation biodosimetry testing, BARDA (Biomedical Advanced Research Development Authority), a division of Health and Human Services of the United States Government, invested more than $365 million since 2009 in the development of next generation radiation biodosimetry tools. In 2016, BARDA awarded DxTerity Diagnostics up to $150 million for the advanced development and delivery of REDI-Dx, a gene expression-based biodosimetry test, for potential placement in the U.S. Strategic National Stockpile (SNS) through 2026.
REDI-Dx fulfills the following critical unmet needs:
• Prioritizes treatment of those likely to develop Acute Radiation Syndrome (ARS)
• High throughput testing mediates surge volumes of potentially affected individuals
• 6-hour processing time to support urgent medical management needs
REDI-Dx provides a quantitative estimate of an individual’s absorbed radiation dose after a nuclear event from an ambient shipped post-event blood sample, which is stable for up to 14 days. This greatly simplifies response logistics. The REDI-Dx test can be analyzed using Thermo Fisher’s existing install base of ABI™ 3500xL Dx Genetic Analyzers with associated REDI-Dx Biodosimetry Interpretive Software. Each high throughput instrument can process over 1,000 samples per day, enabling a capacity of tens of thousands per week on existing infrastructure.
While no one can predict what might occur after a radiological event, nor the precise nature of what our emergency response will be, recognizing the gaps in our current preparedness and technologies is crucial to developing well-laid plans, mitigating casualties, and being as prepared as possible for what might come next.
REDI-Dx is CE-IVD marked.
Not for Sale in the USA. Limited by United States law to investigational use only.
*The development of REDI-Dx® has been funded in whole or in part with Federal funds from the Biomedical Advanced Research and Development Authority, Office of the Assistant Secretary for Preparedness and Response, Office of the Secretary, Department of Health and Human Services, under Contract No: HHSO100201000001C and HHSO100201600034C.